Codex Threads

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful behavioral context beyond this by specifying the threads are 'persistent local' and clarifying that the tool does not reconstruct live events. This is substantial but does not cover all edge cases (e.g., pagination errors, data source specifics), so a 4 is appropriate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with an unambiguous summary, and no wasted words. Every sentence earns its place: the first states the main actions, the second clarifies an important behavioral boundary.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's dual mode (list/read) and the presence of six documented optional parameters plus comprehensive annotations, the description adequately covers the main purpose and an important caveat. It could briefly mention what the read returns when include_turns is false, but the schema handles this. Overall, it is complete enough for an AI agent to select and invoke correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all parameters. The description adds a small amount of context by naming 'thread/list' and 'thread/read' modes, but this is largely redundant with the schema's thread_id description. Baseline 3 applies because the description does not substantially compensate beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses specific action verbs 'List or search' and 'read', names the resource ('persistent local Codex threads'), and explicitly scopes behavior with 'This does not reconstruct live Bridge events.' It clearly distinguishes from siblings by indicating it handles listing/reading rather than per-thread actions.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description states when to use the tool (to list/search/read persistent local threads) and provides an exclusion ('does not reconstruct live Bridge events'). However, it does not explicitly name an alternative sibling or provide a direct contrast with other tools, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.